Check valve having integrally formed seat and seal body

ABSTRACT

A valve assembly includes first and second conduits having respective first and second flanges in abutment with each other, a stopper in the second conduit, and a valve body secured between the first and second flanges. The valve body includes a body bore in communication between the first and second conduits. The body bore defines a circular opening in one end of the valve body. The valve body also includes a circumferential notch that substantially insulates the circular opening from distortion arising from securing the valve body. The stopper snuggly seats against the circular opening to prevent fluid flow from the second conduit to the first conduit, but unseats to permit fluid flow from the first conduit to the second conduit. An o-ring may surround a portion of the valve body and be energized as the valve body is secured. A lip may surround the circular opening to provide a seat for the stopper.

BACKGROUND

The present invention relates to a check valve having an integrallyformed seat and seal body.

SUMMARY

The invention provides a valve assembly, which may be used in a doublediaphragm pump or other application in which one-way flow of fluid isdesired. The valve assembly includes a first conduit having a firstflange; a second conduit having a second flange abutting against thefirst flange; a stopper; and a valve body. The valve body includes acircumferential notch that divides the body into first and secondportions between the notch and respective first and second opposite endsof the body. The valve body also includes a body bore extending throughthe valve body between the first and second ends. The body bore definesa circular opening in the second end of the body, and communicatesbetween the first and second conduits. During assembly, the valve bodyis secured between the first and second flanges and the notchsubstantially insulates the circular opening from distortion arisingfrom such securing. The stopper snuggly seats against the circularopening to prevent fluid flow through the body bore from the second endto the first end, and unseats from the circular opening to permit fluidflow through the body bore from the first end to the second end.

An o-ring may be positioned around the first portion of the valve body.The first portion of the valve body may include a tapered surface thatis of smaller diameter at the first end of the valve body and increasesin diameter to the notch. As the valve body is secured between the firstand second flanges, the tapered surface is forced into the o-ring. Thisenergizes the o-ring to fluid-tightly seal between the valve body andthe first and second flanges.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a double diaphragm pump embodying thepresent invention.

FIG. 2 is a cross-section view of the pump taken along line 2-2 in FIG.1.

FIG. 3 is a cross-section view of a portion of the pump taken along line3-3 in FIG. 1.

FIG. 4 is an exploded view of a check valve assembly of the pump.

FIG. 5 is another exploded view of the check valve assembly.

FIG. 6 is a perspective view of a valve body of the valve assembly.

FIG. 7 is a side view of the valve body.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. Unless specified or limited otherwise, theterms “mounted,” “connected,” “supported,” and “coupled” and variationsthereof are used broadly and encompass both direct and indirectmountings, connections, supports, and couplings. Further, “connected”and “coupled” are not restricted to physical or mechanical connectionsor couplings.

FIGS. 1 and 2 illustrate a double diaphragm pump 10 having a housingdefining two working chambers 15. Each working chamber 15 is dividedwith a flexible diaphragm 20 into a pumping chamber 25 and a motivefluid chamber 30. The diaphragms 20 are interconnected through a shaft35 for synchronized reciprocating movement, such that when one diaphragm20 is moved to increase the volume of the associated pump chamber 25,the other diaphragm 20 is simultaneously moved to decrease the volume ofthe associated pump chamber 25. The pump 10 includes an inlet for thesupply of a motive fluid (e.g., compressed air or another pressurizedgas) and a valve 45 for alternatingly supplying the motive fluid to themotive fluid chambers 30 to drive reciprocation of the first and seconddiaphragms 20 and the shaft 35. Simultaneously with supplying the motivefluid to one of the motive fluid chambers 30, the valve 45 places anexhaust assembly 50 in communication with the other motive fluid chamber30 to permit motive fluid to be expelled therefrom.

In operation, as the diaphragms 20 and shaft 35 reciprocate, the pumpchambers 25 alternatingly expand and contract to create respective lowand high pressure within the respective chambers 25. The pump chambers25 communicate with an inlet manifold 55 that is connected to areservoir containing a fluid to be pumped, and also communicate with anoutlet manifold 60 that is connected to a receptacle for the fluid beingpumped. Check valve assemblies 65 ensure that the fluid being pumpedmoves only from the inlet manifold 55 toward the outlet manifold 60.When one of the pump chambers 25 expands, the resulting negativepressure causes the upper check valve assembly 65 associated with thepump chamber 25 to close, causes the lower check valve assembly 65associated with the pump chamber 25 to open, and draws fluid from theinlet manifold 55 into the pump chamber 25. Simultaneously, the otherpump chamber 25 contracts, which creates positive pressure that causesthe lower check valve assembly 65 associated with the pump chamber 25 toclose, causes the upper check valve assembly 65 associated with the pumpchamber 25 to open, and forces fluid into the outlet manifold 60.

Each check valve assembly 65 has a similar construction, which isillustrated in FIGS. 3-5. The check valve assembly 65 includes a firstconduit 100 having a first flange 105, a second conduit 110 having asecond flange 115 and abutting against the first flange 105, a stopper120, a valve body 125, and an o-ring 130. In FIGS. 3-5, the firstconduit 100 communicates with one of the pump chambers 25 and the secondconduit 110 communicates with the outlet manifold 60. In the lower checkvalves 65, the first conduit 100 would communicate with the inletmanifold 55 and the second conduit 110 would communicate with one of thepump chambers 25. The use of “first” and “second” to describe theconduits 100, 110 is arbitrarily chosen to follow the order anddirection in which fluid flows through these conduits (i.e., the checkvalve assemblies 65 permit flow from the first conduit 100 to the secondconduit 110, but not from the second conduit 110 to the first conduit100). The second flange 115 includes first and second steps 140, 145.The second conduit 110 begins above the second step 145. The illustratedstopper 120 is a ball, but in other embodiments may be a stopper havingother shapes and may include an at least partially spherical surface tofacilitate sealing against the valve body 125.

With reference to FIGS. 6 and 7, the valve body 125 is constructed asone piece from a nonmetallic material, which in some embodiments may bean elastomeric material. The valve body 125 has a circumferential notch150 in an outer surface. The valve body 125 has a first portion 155between the notch 150 and a first end 160 of the valve body 125, and asecond portion 165 between the notch 150 and a second end 170 of thevalve body 125. A body bore 175 extends through the valve body 125between the first and second ends 160, 170 and communicates between thefirst and second conduits 100, 110. The body bore 175 defines a circularopening 177 in the second end 170 of the body. A lip 180 surrounds thecircular opening 177 and defines a generally conical seat surface. Whenthe stopper 120 is drawn against the lip 180 (e.g., when the pressure inthe first conduit 100 is lower than the pressure in the second conduit110), the lip 180 deflects to provide a substantially fluid-tight sealaround the at least partially spherical surface of the stopper 120. Thelip 180 therefore facilitates sealing the circular opening 177 with thestopper 120.

The first and second flanges 105, 115 each include a mating face 185,190, respectively. The mating faces 185, 190 abut against each otherwhen the pump 10 is assembled. Fasteners 195 extend through holes in theflanges 105, 115, and nuts 200 are threaded onto the fasteners 195 tosecurely hold the mating faces 185, 190 against each other. The firstconduit 100 is of smaller diameter than the second conduit 110. Spacesare defined between the steps 140, 145 and the mating face 185 of thefirst flange 105.

The o-ring 130 fits into the space between the mating face 185 and thefirst step 140, which space is slightly smaller than the cross-sectionaldiameter or height of the o-ring 130 material so that the o-ring 130 isslightly compressed or deflected. The top of the first portion 155defines an enlarged surface of slightly larger diameter than that of thesecond portion 165, and the first portion 155 has a tapered surfacebetween the notch 150 and the first end 160 of the valve body 125. Thetapered surface is of smaller diameter at the first end 160 of the valvebody 125 and increases in diameter to the notch 150. The tapered surfacetapers at a 10° angle in the illustrated embodiment.

The valve body 125 fits into the space between the mating face 185 andthe second step 145, with the first end 160 abutting against the matingface 185 and the second end 170 abutting against the step 145. The lip180 of the valve body 125 extends into the second conduit 110 and thestopper 120 is movable within the second conduit 110 to seat and unseaton the lip 180. The space between the mating face 185 and the secondstep 145 is equal to the distance between the first and second ends 160,170 of the valve body 125 so that the valve body 125 is securelyretained between the second step 145 and the first mating face 185. Theinner diameter of the o-ring 130 is slightly smaller than the outerdiameter of the first portion 155 at the first end 160, such that thetapered surface energizes the o-ring 130 as the valve body 125 is pushedagainst the o-ring 130. The o-ring 130 is backed up against the secondflange 115 within the first step 140, and fluid-tightly seals againstsuction and positive pressure that may cause fluid to flow around theoutside of the valve body 125 between the first and second conduits 100,110 in the absence of the o-ring 130.

The first and second portions 155, 165 seal between the first and secondflanges 105, 115, and the lip 180 provides a seat for the stopper 120.In this regard, the valve body 125 is integrally-formed as a singlepiece with seat and seal portions. During assembly, the valve body 125may be slightly deformed as it energizes the o-ring 130. The notch 150absorbs some of the distortion in the valve body 125 to maintain thecircularity of the circular opening 177 and the conical shape of theconical surface of the lip 180. In this regard, the notch 150 may besaid to “insulate” the circular opening 177 and lip 180 from distortionto facilitate a snug seal for the stopper 120. The stopper 120 preventsfluid flow through the body bore 175 from the second end 170 to thefirst end 160. Flow through the body bore 175 from the first end 160 tothe second end 170 unseats the stopper 120 from the lip 180 to permitfluid flow from the first conduit 100 into the second conduit 110.

It should be noted that, although the illustrated embodiment applies thecheck valve of the present invention to a double-diaphragm pump, theinvention is applicable to substantially any other embodiment in which acheck valve is desirable to create one-way flow between first and secondconduits. Various features and advantages of the invention are set forthin the following claims.

1. A valve assembly comprising: a first conduit having a first flange; asecond conduit having a second flange abutting against the first flange;a stopper; and a valve body secured between the first and secondflanges, the valve body including a circumferential notch that dividesthe body into first and second portions between the notch and respectivefirst and second opposite ends of the body, a body bore extendingthrough the valve body between the first and second ends, the body boredefining a circular opening in the second end of the body, the body borecommunicating between the first and second conduits; wherein the notchsubstantially insulates the circular opening from distortion arisingfrom securing the valve body between the first and second flanges; andwherein the stopper snuggly seats against the circular opening toprevent fluid flow through the body bore from the second end to thefirst end, and unseats from the circular opening to permit fluid flowthrough the body bore from the first end to the second end.
 2. The valveassembly of claim 1, further comprising an o-ring around the firstportion of the valve body; wherein the first portion of the valve bodyincludes a tapered surface that is of smaller diameter at the first endof the valve body and increases in diameter to the notch; and whereinsecuring the valve body between the first and second flanges forces thetapered surface into the o-ring and energizes the o-ring tofluid-tightly seal between the valve body and the first and secondflanges.
 3. The valve assembly of claim 2, wherein the second flangeincludes first and second steps; wherein the o-ring is secured betweenthe first step and the first flange; and wherein the valve body issecured between the second step and the first flange.
 4. The valveassembly of claim 3, wherein the first end of the valve body abutsagainst the first flange and the second end of the valve body abutsagainst the second step.
 5. The valve assembly of claim 1, wherein thevalve body includes an integrally-formed lip surrounding the circularopening and extending from the second end of the valve body into thesecond conduit; wherein the stopper is positioned within the secondconduit; and wherein the lip provides a seating surface for the stopperto facilitate sealing therebetween.
 6. The valve assembly of claim 5,wherein the seating surface of the lip is generally conical in shape;and wherein the notch insulates the lip from distortion arising fromsecuring the valve body between the first and second flanges.
 7. Thevalve assembly of claim 1, wherein the valve body is constructed as onepiece from a nonmetallic material.
 8. A double-diaphragm pump forpumping a fluid to be pumped from reservoir to a receptacle, the pumpcomprising: first and second working chambers; a diaphragm in each ofthe working chambers and dividing each working chamber into a pumpingchamber and a motive fluid chamber; a shaft interconnecting thediaphragms for synchronized reciprocating movement; a valvealternatingly placing one of the motive fluid chambers in communicationwith a source of pressurized motive fluid while placing the other motivefluid chamber in communication with an exhaust assembly; an inletmanifold communicating with the pumping chambers and adapted tocommunicate with the reservoir; an outlet manifold communicating withthe pumping chambers and adapted to communicate with the receptacle; acheck valve assembly operatively positioned between each pumping chamberand each of the inlet and outlet manifolds, each check valve assemblyincluding a first conduit having a first flange, a second conduit havinga second flange abutting against the first flange, a stopper, and avalve body; wherein the valve body includes a circumferential notch thatdivides the body into first and second portions between the notch andrespective first and second opposite ends of the body; wherein the valvebody includes a body bore extending through the valve body between thefirst and second ends, the body bore defining a circular opening in thesecond end of the body, the body bore communicating between the firstand second conduits; wherein the notch substantially insulates thecircular opening from distortion arising from securing the valve bodybetween the first and second flanges; and wherein the stopper snugglyseats against the circular opening to prevent fluid flow through thebody bore from the second end to the first end, and unseats from thecircular opening to permit fluid flow through the body bore from thefirst end to the second end.
 9. The pump of claim 8, further comprisingan o-ring around the first portion of the valve body; wherein the firstportion of the valve body includes a tapered surface that is of smallerdiameter at the first end of the valve body and increases in diameter tothe notch; and wherein securing the valve body between the first andsecond flanges forces the tapered surface into the o-ring and energizesthe o-ring to fluid-tightly seal between the valve body and the firstand second flanges.
 10. The pump of claim 9, wherein the second flangeincludes first and second steps; wherein the o-ring is secured betweenthe first step and the first flange; and wherein the valve body issecured between the second step and the first flange.
 11. The pump ofclaim 8, wherein the first end of the valve body abuts against the firstflange and the second end of the valve body abuts against the secondstep.
 12. The pump of claim 11, wherein the valve body includes anintegrally-formed lip surrounding the circular opening and extendingfrom the second end of the valve body into the second conduit; whereinthe stopper is positioned within the second conduit; and wherein the lipprovides a seating surface for the stopper to facilitate sealingtherebetween.
 13. The pump of claim 12, wherein the seating surface ofthe lip is generally conical in shape; and wherein the notch insulatesthe lip from distortion arising from securing the valve body between thefirst and second flanges.
 14. The pump of claim 8, wherein the valvebody is constructed as one piece from a nonmetallic material.
 15. Amethod for assembling a valve assembly for providing one-way flow from areservoir to a receptacle, the method comprising the steps of: providingfirst and second conduits having respective first and second flanges;providing a stopper; providing a valve body having first and secondopposite ends and a body bore extending between the first and secondends, the body bore defining a circular opening in the second end;forming a circumferential notch in the valve body to divide the bodyinto first and second portions between the notch and the respectivefirst and second ends; securing the valve body between the first andsecond flanges with the first end abutting the first flange and thesecond end abutting the second flange, and with the body borecommunicating between the first and second conduits; accommodatingdistortion of the valve body with the notch to insulate the circularopening from distortion as the valve body is secured; and placing thestopper in the second conduit such that the stopper snuggly seatsagainst the circular opening to prevent fluid flow through the body borefrom the second end to the first end, and unseats from the circularopening to permit fluid flow through the body bore from the first end tothe second end.
 16. The method of claim 15, further comprising forming atapered surface in the first portion of the valve body, the taperedsurface having smaller diameter at the first end of the valve body andincreasing in diameter to the notch; positioning an o-ring around thetapered surface; and forcing the tapered surface into the o-ring uponsecuring of the valve body between the first and second flanges toenergize the o-ring to fluid-tightly seal between the valve body and thefirst and second flanges.
 17. The method of claim 16, further comprisingforming first and second steps in the second flange; securing the o-ringbetween the first step and the first flange; and securing the valve bodybetween the second step and the first flange.
 18. The method of claim15, further comprising integrally forming a lip around the circularopening in the valve body; extending the lip into the second conduit;and providing a seating surface for the stopper with the lip.
 19. Themethod of claim 18, wherein providing a seating surface with the lipincludes defining a generally conical seating surface with the lip; themethod further comprising insulating the lip from distortion arisingfrom securing the valve body by accommodating distortion of the valvebody with the notch.
 20. The method of claim 15, wherein providing avalve body includes constructing the valve body as one piece from anonmetallic material.